Tag Archives: environmental engineering

Q&A with Ali Khatami – Jet Cleaning Leachate Collection Pipes

August 21, 2019

I read your informative blog regarding recommendations for jet cleaning leachate collection pipes. I have a question.

QUESTION: Say a landfill only has access to one end of a leachate pipe. This would be a situation where a new cell was built, where the uphill side of the cell butts up against an existing, pre-subtitle D cell with no leachate collection pipe. In other words, the uphill side of the new leachate pipe simply terminates rather than tie into an existing pipe.

To add to the issue, no vertical cleanout/riser pipe was installed on the uphill end (as this may impede waste operations in the area). There are of course riser and cleanout pipes and a sump on the downhill side for normal leachate collection. I would imagine that pumping water from the accessible side would push out any solids through the perforations into the leachate aggregate bedding, and may cause clogging there.

 Is it possible, or reasonable, to flush this new leachate line?


ANSWER: There is always a possibility that a portion of dislodged material from the interior walls of the pipe will pass through pipe perforations and enter the gravel bedding around the pipe. However, due to the pipe slope, the great majority of the separated material flows down the pipe to the lowest point where it can be removed using a vac-truck.

Keep in mind also that, it’s true that leachate can partially flow through the bedding gravel toward the sump, but the role of the gravel is primarily protecting the pipe against compressive loads of waste above. Partial clogging of gravel around the pipe should not be considered as a malfunction of the system. Partial clogging of gravel normally may occur near the bottom portion of the gravel pack, which still allows leachate flow through gravel to pipe perforations above any clogged zone below.

In several instances, when a portion of a leachate collection pipe was opened up after being in service for a while, it did not support the idea of a clogged zone in the gravel pack. What was observed, included discolored gravel due to fine particles settling (from filtered leachate through geotextile) on gravel particles and a bit of the same particles near the bottom of the gravel pack.

I’ve never observed severe clogging of the gravel pack.

Thanks for your interest in the subject, and please stay in touch with any other questions. SCS freely shares best practices and advice within our industry; email us at service@scsengineers.com


About the Author: Ali Khatami, PhD, PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. He is also our National Expert for Landfill Design and Construction Quality Assurance. He has over 40 years of research and professional experience in mechanical, structural, and civil engineering.





Posted by Diane Samuels at 6:00 am
Tag Archives: environmental engineering

What’s in your water? Protecting potable water from ‘forever chemicals’

August 19, 2019

Perfluoroalkyl and polyfluoroalkyl substances collectively referred to as PFAS or “forever chemicals,” are being detected in water and many types of foods. Viraj deSilva of SCS Engineers provides an overview of sources, treatment processes used to remove them from wastewater, and government advisory limits in this recent article in World Water Magazine.

PFAS is extremely persistent in the environment and includes more than 4,500 synthetic chemicals, are organic compounds whose hydrogen atoms are replaced by fluorine. The bonds between fluorine and carbon are extremely strong and difficult to break.

The two main PFAS compound structures are perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). PFOA and PFOS are no longer manufactured or used in the US, but similar replacement chemicals (such as GenX) remain. Other countries still manufacture PFAS and many consumer products imported to the US from those countries still contain the compounds.

About 610 locations in 43 US states serving an estimated 19 million people have PFAS in the drinking water, according to the Environmental Working Group and the Social Science Environmental Health Research Institute at Northeastern University in Boston, Massachusetts, United States (US). See the full references in the article.

The current US Environmental Protection Agency (EPA) health advisory limit is 70 parts per trillion. However, as an advisory level, it is not enforced – meaning that the water is not required to be tested for PFAS compounds. The US Food and Drug Administration (FDA) confirmed that forever chemicals were detected in many foods. The FDA tested 91 foods, including fresh produce, baked goods, meat, and fish.

Perfluorinated chemicals will continue to be subject to studies, risk assessments, possible regulations, and data collection under several statutes, so product and waste-reduction practices should be considered immediately to reduce potential consequences.

There are solutions to all of these challenges and the new EPA Action Plan; new measures will lead to better protection of potable water from the harmful impacts of forever chemicals.

Take me to the article.








Posted by Diane Samuels at 6:00 am
Tag Archives: environmental engineering

Industrial Stormwater Management: BMP Strategies, Selection, and Implementation at NPDES Regulated Industrial Stormwater Facilities

July 18, 2019

A Tiered Approach for an Increased Regulatory Compliance Trajectory

Under the Clean Water Act (CWA), stormwater regulation is growing, evolving and becoming more robust, with increased compliance standards. For the stormwater managers, consultants and dischargers, the stakes have never been higher. The United States Environmental Protection Agency (US EPA) regulations are in an iterative cycle, facing increased pressure from Non-government organizations (NGOs) to increase water quality standards.

As stakeholders, the stormwater community has come a long way since the Cuyahoga “River on Fire” in 1969. Now Federal regulations at 40 CFR 122.26(b)(14)(i)-(xi) require stormwater discharges associated with eleven (11) specific categories (29 Sectors) of industrial activity to be covered under National Pollutant Discharge Elimination System (NPDES) permits.

Recently noted, the Multi-sector General Permit (MSGP) draft for the year 2020 be significantly altered through a large NGO lawsuit, the US EPA entered into a landmark settlement agreement (Waterkeeper Alliance v. US EPA [2d Cir. 15-02091]).

With an escalation of NPDES industrial stormwater compliance, there must be a pronounced emphasis on reducing and eliminating pollutants of concern in Stormwater Discharge. The fundamental concentration starts with Best Management Practices (BMPs). To achieve compliance to these benchmarks, one must prioritize BMPs to meet a “level of control” which includes achieving Best Available Technology and Best Conventional Technology (BAT/BCT) to reduce industrial discharge pollutants of concern.

For many industrial dischargers, it is no longer viable to adhere to status quo BMPs. In many cases, it is more feasible to approach escalating regulatory compliance with an eye to the future, by thoughtfully seeking long term and sustainable solutions. Industrial stormwater BMPs and their associated implementation is the critical path towards regulatory compliance. Data, including internal sampling, matched up with BMP targeted pollutant specifications has to be continually collected and reviewed in light of US EPA Benchmarks.

Increased Water Quality Objectives for 303d and Total Maximum Daily Loads (TMDLs) can and have increased receiving body benchmarks to Numeric Effluent Limits (NELs). Over the last five years, several states adoptions of State Industrial General Permits (Washington, California, and Oregon) have been comprised of stakeholder input regarding NELs, and in many cases, the outcome was a lesser standard of Numeric Action Limits or NALs. However, based on the recent Waterkeeper Alliance Settlement, studies concerning the viability of NELs are imminent, and therefore NELs are becoming more prevalent.

Never before has BMP selection and implementation been more important.

At Jonathan’s session at StormCon 2019, he will discuss the challenges of the industrial regulations and associated escalation scenarios, and provide a review of compliance numbers for the dischargers seen as “case studies” for the emerging regulatory trends. He will show facilities with advanced BMPs and how they have come to terms with Industrial Stormwater compliance.


Presenter at StormCon 2019: Jonathan J. Meronek, QISP, IGP-ToR, CPESC, CISEC, QSP/D

StormCon 2019 Information

Stormwater Management





Posted by Diane Samuels at 6:05 am
Tag Archives: environmental engineering

Employee Training Under PSM/RMP – Tackle It

July 10, 2019

Bill Lape discusses the most frequently asked questions about designing a training program that is part of your facility’s PSM and RMP programs and provides a defensible position during inspections while ensuring that your facility operators and maintainers perform their jobs safely.

  • Who is covered under the PSM and RMP regulations for training?
  • What training do they need?
  • How often do they have to be trained?
  • How can this training be conducted?
  • How do I evaluate their understanding of the material?

Bill tackles all your questions in this article.  Set-PSM-RMP-Hut-Hut




Posted by Diane Samuels at 6:03 am
Tag Archives: environmental engineering

Choosing the Right Landfill Designer is Crucial to an Operator

July 9, 2019

Operators know that selecting a Landfill Designer involves careful consideration of the designer’s experience and knowledge of construction to control costs and capital outlay.

Landfill operators usually seek to pay the lowest price for design work. While this is in line with the competitive market models, operators need to be sure that the designer’s experience lines up with their desired outcome, or problems may arise later for the operator. If the designer’s general or specific experience in the region is lacking, reconsider your selection parameters.

General experience is the comprehensive knowledge of landfill design and the development of expertise gained on similar projects over an extended period. A few project experiences in the remote past do not adequately qualify a designer. Experience in the region means that your designer has designed and developed similar projects in the larger vicinity of the project.

Regional experience demonstrates that the designer has significant knowledge of geology, hydrogeology, climatology, and available constructions materials in the area. Without this level of experience and understanding, the operator risks ending up with a system that does not function well and may be susceptible to environmental conditions, causing excessive project maintenance costs over time.

I recommend that operators work with a known entity; look for a designer who has done similar projects on numerous occasions in your region, and who can provide proof of their experience and knowledge to design according to your specific goals. A designer may not meet the criteria of the least expensive vendor, but a properly designed and constructed project can save a tremendous amount of money by:

  • Avoiding design mistakes during construction
  • Ensuring proper integration with existing systems and technologies
  • Avoiding exorbitant O&M costs later

Landfills are unique systems that require explicit design and construction criteria in order to operate seamlessly and safely for a very long period of time. Developing landfills generally takes several decades to complete and requires a substantial amount of knowledge and design consistency to ensure that the various landfill components function together.

Some operators change designers every few years without realizing that they risk inconsistencies in the design and construction every time a new designer comes into the picture. For this reason, I recommend that operators find the most qualified designer who is also very familiar with the construction and field maintenance of similar projects, and then stick with that designer for a long time.

At times, several different designers may be involved with various components of the landfill. To improve design consistency, I recommend that the most experienced design group review each design package regularly in order to help eliminate inconsistencies, improve the overall design integrity, and facilitate proper operation of the constructed systems during operation.

Landfill Design-Build-OM&M

About the Author: Ali Khatami, Ph.D., PE, LEP, CGC, is a Vice President of SCS Engineers and the firm’s National Expert for Landfill Design, CQA, and Elevated Temperature Landfills (ETLFs). Ali has 40+ years of research and professional experience in mechanical, structural, and civil engineering acquiring extensive experience and knowledge in the areas of geology, hydrogeology, hydrology, hydraulics, liquids management, construction methods, material science, construction quality assurance (CQA), and stability of earth systems.

He applies his experience in the siting of numerous landfills and the remediation of hazardous waste contaminated sites. Ali’s expertise includes the design and permitting of civil/environmental projects such as surface water management systems, drainage structures, municipal solid waste landfills, hazardous solid waste landfills, low-level radioactive waste landfills, leachate and wastewater conveyance, and treatment systems.
His cross-practice experience includes the design of gas collection and disposal systems, hazardous and non-hazardous waste impoundments, storage tank systems, waste tire processing facilities, composting facilities, material recovery facilities, leachate evaporator systems, and liquid impoundment floating covers.





Posted by Diane Samuels at 6:05 am
Tag Archives: environmental engineering

SCS Engineers Storm the Beach – Run, Walk, Roll for U.S. Vets

June 28, 2019

SCS Engineer’s Long Beach Headquarters sponsored and participated in the U.S. Vets Storm the Beach 5K/10K  Run, Walk & Roll for Veterans event in Long Beach, CA.

U.S. Vets is an impressive organization supporting our Veterans in Long Beach, many of whom are homeless.  These men and women who have served our country receive housing, employment opportunities, and counseling services from this private non-profit organization. Please click here in order to learn about U.S. Vets.

Participating this year, left to right: Sonia Aguirre, Wendy Mendoza, Sara Garcia and husband, Brendan McGarrity, Jennifer McCafferty, Stacey Dolden, Deidra McGrew and Hanna Suh and friend.



Visit our website and look for careers with our award-winning team of professionals.



Posted by Diane Samuels at 6:00 am
Tag Archives: environmental engineering

SCS Engineers Welcomes Dana Justice to Phoenix, AZ

June 21, 2019

SCS Engineers’ Arizona office is continuing to grow with the addition of Dana Justice, a marketing specialist, who previously worked at the award-winning firm’s office in San Diego.

“Dana brings fresh ideas, strong problem-solving skills, and creative business development tactics to the Arizona office,” said Dan Sola, Arizona project director of SCS Engineers.

Justice is responsible for supporting marketing and business development in Arizona, Nevada, and California for environmental services. Her job responsibilities include engaging in business development outreach and continuing to strengthening the firm’s client success culture. As an employee-owned environmental consultant and contractor, SCS excels at accomplishing specific technical needs and high quality but also strives to provide a superior working relationship with their clients.

“SCS has great company culture with a sense of family among the staff,” Justice said. “I’m thrilled to take on a larger role in the Southwestern region and new responsibilities at SCS.”

Justice earned a bachelor’s and master’s in business administration from California State University San Marcos. She lives in Mesa.

The Arizona office has completed 3,500 projects during the last 30 years for the solid waste industry, government, and other industries responsible for safeguarding the environment as part of doing business.




Posted by Diane Samuels at 6:00 am
Tag Archives: environmental engineering

2019 Missouri Environmental Conference July 14 – 16

June 3, 2019

SCS Engineers is looking forward to seeing you at the 2019 Missouri Environmental Conference, July 14-16, at the Margaritaville Lake Resort in Osage Beach, Missouri.

This year the conference includes a full Brownfields track, sessions on Tanks, Land Development, Legal, Solid Waste and Environmental Services. Four SCS professionals will be presenting on the following topics:

Registration details are here.

MONDAY JULY 15, 10:30 AM
A Balancing Act – The Many Requirements at a Modern Landfill – Doug Doerr, P.E., SCS Engineers As landfills have become more complex, they have also become subject to more rules, regulations, and requirements. Many times the involvement of different groups with different requirements and end goals lead to a well-run facility that is very environmentally protective. However, many times owners and operators find themselves trying to balance different, and sometimes competing, requirements. This presentation will discuss some of the instances when conflicts exist and provide insights on how to find balance.

Injection Wells for Responsible Liquids Management – Stephanie Hill, SCS Engineers This presentation will highlight two case studies where deep well injection is being used to manage non-hazardous industrial wastewater at (1) an underground coal mine and (2) leachate from a landfill. This side-by-side comparison of each of these industry’s differing approaches will walk through their unique wastewater type and how they manage chemical compatibility of their injected wastewater and downhole reservoir fluids to ensure the longevity of this capital asset.

Also at 8:30 AM 
PFAs in Landfill Leachates – Overview and Handling Options – Viraj deSilva, Ph.D., P.E., BCEE, SCS Engineers With the EPA positioned to take serious action on PFAS in late 2019, regulators in many states have already begun implementing measures of their own, while state and federal courts are beginning to address legal issues surrounding this emerging contaminant. These changes mean new potential liabilities and consequences for organizations that manufacture, use, or sell PFAS or PFAS-containing products, and the time to take action to protect your operations is now. A number of established treatment options to remove PFAS from landfill leachate are available, including activated carbon, ion exchange or high-pressure membrane systems.

Design and Construction of a ClosureTurf® Final Cover System – Dillon Baird, P.E., SCS Engineers As onsite borrow sources become depleted and Subtitle D landfills reach capacity and close, synthetic final cover systems such as ClosureTurf® are now being utilized as an alternative to a prescriptive final cover system. The construction and long term postclosure maintenance costs of final cover systems are crucial factors when selecting which cover system is best for a site. Mr. Baird’s presentation will provide a recap of the value engineering process that led to the construction of a ClosureTurf® final cover system. Additionally, he will share some of the lessons learned during each phase of the project.






Posted by Diane Samuels at 6:00 am
Tag Archives: environmental engineering

Wendell Minshew Captures the Essence of SCS’s Purpose

May 31, 2019

Wendell, a Senior Project Professional in the SCS Engineers Sacramento office became interested in photography 35 years ago. He had broken his ankle and needed something to do because he felt grumpy not being able to play tennis. His tennis partner loaned him a camera, some film, and his dark room.

Wendell was hooked.

Wendell’s beautiful photos capture the reason we work with our clients to protect our environment. See a few pieces of his organic work, and look for more soon.

Mr. Minshew has over 30 years of engineering experience. He specializes in civil engineering services in the planning, design, permitting, and construction management of solid and hazardous waste facilities. He is a licensed Professional Engineer in California and Nevada.

Thank you for sharing, Wendell.





Posted by Diane Samuels at 6:01 am
Tag Archives: environmental engineering

Cost Reduction Tips for O&G Groundwater Monitoring

May 20, 2019

For many oil and gas waste processing and disposal facilities, and water midstream facilities, groundwater monitoring is mandatory. The ongoing quarterly monitoring well sampling is a long-term operating expense that presents opportunities for cost reduction by employing new sampling technologies that reduce labor time and cost.

Conventional monitoring well sampling traditionally requires bulky and expensive pumps and support equipment. Time-consuming to use, these also require specialized training and are prone to mechanical failure in oil basin extreme weather conditions. Straightforward, lower-tech methods are available that can substantially lower field costs; in some cases, by up to 50 percent.

Best Practices

If your sampling results indicate potential problems, we recommend bringing in groundwater analytic expertise; this is where you want to concentrate your environmental compliance resources.

It is essential to conduct one or more background sampling events before a facility opening to interpret sampling results that may reveal facility issues. At SCS, we’ve seen many documented cases of facilities that unknowingly were operating over groundwater already contaminated by other nearby facilities or tainted by naturally occurring petroleum in the subsurface.

Another cost-reduction best practice is the application of statistical analysis to the lab results. While not always required by regulators, there are well-proven analytical tools that can answer questions about the source of apparent anomalies in the data. Ongoing application of these tools—even if only done internally—can reveal problems early and solve others before they become a liability.

O&G Environmental Services and Permitting

Jim Lawrence, SCS Engineers professional hydrogeologist

About the Author: James Lawrence of SCS Engineers is a hydrogeologist with 25 years of experience in all aspects of the distribution and movement of groundwater in the southwestern and central portions of the U.S. Jim leads the groundwater monitoring program for SCS in the Permian Basin area. He works to resolve problems that arise with groundwater monitoring, including assessment monitoring, corrective action, landfill and natural gases, and alternate source demonstration issues.

His responsibilities include supervising the sampling, data reporting, and statistical analysis. His job experience includes extensive permitting-related hydrogeological characterizations, the design and implementation of groundwater monitoring systems, assessing groundwater geochemistry, soil and groundwater assessment investigations, risk reduction rules, groundwater modeling, design and implementation of numerous large dewatering systems, design of water supply wells, managing waste injection wells, managing CERCLA and RCRA investigations, and waste analysis/characterization programs.

Ask Jim






Posted by Diane Samuels at 6:00 am
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